Dynamometer roll shields



April 2, 1946. H. 1 BENNETT l DYNAMOMETER ROLL SHIELDS Original FiledFeb. 19, l1.941 2 Sheets-'Sheetl 1 l l l z Zmverxtor B Harold L.Benrer'f u l 4 v 'I Gttomeg:

April 2, 1946. H. l.. BENNETT DYNAMOMETER ROLL SHIELDS Original FiledFeb'. 19, 1941 42 Sheets-Sheet 2 Harold L. Benne'H' Gttornegf PatentedApr. 2, 1946 :rncsnse assignments, to Bennett-Feragen, Inc., "Seattle,Wash., a corporation of Washington originali applicationrebruary 19,1941, serial No.

V1-3 Claims.

This invention .relates -to devi e tor testing the power andfallitd.tharatttristcs. Of en ant@- mnble the automobile 'Wt-reels, whereof areCredled between pairs of `rolls, andmcre particular- 1y .concerns the.-prnvisions for envnathe. entnmOble-Off Such proll, Whh @testing We 10tated by the automobile wheels. vThe Aprese-:nt invention is a divisionfrom my application ASerial No. 379,581, sled February 19,1941. i l

In such devices `the whe'elfcradling rolls kdrive an absorption unit,usual-ly a hydraulic absorption dynamometer, which :is suitablyconnected to and associated with `indicating mechanism to determine thepower characteristics and related characteristics of the automobileengine. The driving wheels of the automobile. must vbe so cradled in thedriving. rolls oi 'theassembly that, regardless of the speed-or ,powerdeveloped, the automobilewheels will not climb upon nor leave the rolls.However., .when atestis completed it .is desirable that the automobilebe able to back "01T from the rolls, or in some instances to continueforwardly past the rolls,under its own power; It is desirable, in apreferred arrangement, Athat the movement of the .automobile 01T therolls be 'automatic to the extent that it is only necessary to reversethe direction `of rotation of the wheels, and v.so that no attention onthe .part of the o perator or attendant isr required` vto permit thebacking off of the automobile.

The attainment of the above ejnlds in a simple, reliable manner, bymechanism readily associated with such a dynamometer, is the 'aim of thepresent invention.

In the atonlpenying' drawings"my invention has been'showninassociation'with a typical dynanometer, and has been illustrated in varient formsof execution? l Figure 1 is' .a plan View. .Showing .Parts broken away,of a typical dynamometer device with roll shields associated therewithsuch las are automentally brought .into operative position by the action.of Abarking nn and. .Figure 11..A n View Simile? 1.30 Figure 1, .shQWig. @9V/@Very power mechanism for effecting the movement into 'andfrom operative positionoi the roll shields.

Figure 2 is Va transverse section taken substantially aiongthe line 2--2of Figure 1, and

or Figure 1A..

Figure 3I is a section, generaily similar to Figure 2-, illustrating adifferent form of device `tor disengaging the automobilel wheels-fromthe' dynrtrntimtttr':rollt` 'f y Figure 4 is a detail section on theline 4-4 of ividedjand this application July'l,

Figure 1, showing the overrunning clutch-mechanism, and Figure 5 is ravfurther section Vthrough this device taken on the `line5-,-5-of.`1!ig-ure 4.

Figure 6 is Aan end view `of a roll-braking deA vice, serving'as an,substitute for the rolishield shifting device of Figure/i, forexample'.

The dynamometer i2is driven vfrom one of a pair of rolls, including varear roil Iv and a front roll I0 of each pair, whichvaresuitably spaced.for cradling the drivingwheels oflan automobile between them. Such avehicle moves onto Athe rolls in the direction oi the driveon arrow Ashown in Figures l and 2: Continued .forward operation of thedrivingfw'heels, after rthey are cradled between thrnlls' 1| and l1/Willnjr'dnne a tendency `tor ther/herfst@ 'nnb nnonth'e .front 1011 "t t0which the -tynnrnorntr ebtbrntlnn unit 21S tnnnecterl- The' rolls )irotate lfrelvnn their axes, anti-.friction bearings 4I3 vbeing used asrequired, so that in the highest degreepossi ble the entire lresistanceto rotation of the vehicle wheels is createdby governing the rotation ofrolls l0.

The normal installation is of the rpit typef,lalnd this type Vwill bedescribed, aithough the invenf tion may be incorporatedin a door type,if de-v sired.y While various foundations for supporting the rolls andtheir bearings are possible,I Il have devised a Very simple andeffective`mounting, consisting of lfour base Achannels llresting upon the floorof the pit, and each carrying two be'afrf ing supports or pillowblocksJfZ, whiehreceive the anti-friction bearings 1,3-, each bearingeilcircling an end` of a Yhollow r4roil axle I4. rllfhe bearingsupports, as shown bestin Figures 2` and 2A, are received between theupturnedr ilangesof the channels Il, andtheir upper sides may beconnected together by channel (cr preferabiy angle-iron) tieb'ars'lijeach of which overlies a channel Il. On these tie bars viloor-p'lates to cover the pit may be supported. `ASuitable .tie membersextending parallel `to the rolls interconnect the several cross,channels-into a .rigid base structure. Anchor bolts Il hold the-wholeaccurately in place Within the pit. i i

In the 'preferred-form Yof the Aimfenti,on shield plates I6 areprovided,which during atestine*A normally retracted from contact with the wheelW, so that 4they `do `not vinterfere between,v the rolls I9 andthe-wheels resting thereupon, but which are so arranged thatautomatically, 'upon the reversal of the directionof rotation oi thewheels', these shields I5 are arrangedto interpose themselves betweentherroll vand the wheel, and thereby affordtraction for the wheel toclimb out upon. One edge of the shield preferably is curved to overlieand to rest upon a roll. Its other edge is pivotally supported upon armsIl', which are rigidly connected to a rotatable shaft I8, fixed in theframe II. Although such curved plates are preferable, plane plates maybe used.

The vehicle is driven upon therrolls under its own power, and until itsdriving wheels come to rest equally upon the rolls I and IIJ. If itshould Vhappen that the shield plates I6 for the rearl rolls are inoperative or roll-covering position.

as they are shown in Figures l and 2, initial rotation of the vehiclewheels resting upon them,l

in the direction which would normally drive the l' retracted position touncover the rolls. Upon` conclusion of the test, the vehicle normallybacks l vehicle forward, flings the plates backward into ofi', under itsown power. When the vehicle Y, wheels are thus rotated in reverse, therear rolls Atend to revolve in a clockwise direction, as viewed jinFigure 2, but because the'shieldsdo not contact these rolls, nor thewheelscradledthereupon, after being retracted, the shieldscan not bemoved forward by traction between the wheels and shields, in the mannerthat they were retracted. Manual or power mechanism may bev provided tomove the shields again-into operative` .these eccentric disks 9| fromthe shaft is such that the eccentrics may swing freely away from theshaft in the clockwise direction, but can not swing past the shaft in acounterclockwise direction. These eccentrics are urged into -engagementwith the roll shaft by springs/93 reacting from bosses 94 formed in thehousing. For moving and retaining the eccentrics out of such engagementthere may be provided a releasing sleeve 95, having fingers 96interposed between the ec- Y When the eccentrics are so held from vcentrics; engagement, reverse rotation of the roll will not advance theshield into operative position@ A shifting lever or arm 91, which may bemoved by any suitable mechanism, is attached to sleeve 95, as shownyin'rFigure 5; see also Figure 6.

When the fingers 9Bare in the position wherein they are shown in Figure4, however, the

springs 93 will hold the eccentrics in contact with the smooth peripheryof shaft 29. As long as the shaft rotates counterclockwise theeccentrics will merely rub lightly, but engagement-of the shaft with theeccentrics, Aby 'its' initialjrotation in reverse clockwise direction,will tend to swing them counterclockwise. Because, as stated, the

VVspacing' between pivot V92 and the shaft periphposition, and Whilesuch mechanism is shown in Figures 1A and 2A, forv example, preferablythe operation is automatic, and requires no action by the attendant,other than reversal of the direction of rotation of the automobilewheels.

To this end an`automatic overrunrn'ng clutch 9 on roll shaft I4 isconnected to an arm II, rigidly mounted on shaft I8, byfa link I9connectedV tothe arm 98 of the overrunning clutch mechanism; As long asthe/vehicle wheel turns inV its forward driving direction theclutch doesnot engage, but as' soon as the rotationis reversed it grips andSWngsarm II' to turn the shaft I 8 in the directionV to move'thev shields-VIG into or towards roll-covering position. When a shield or coverplate has been moved to a position-above a. rollit may be tractivelyengaged by the wheel Vwhich rests upon that roll. Y V'The shield isrthenc drawn by the wheel intoU the angle between the roll and the contactingvehicle wheel. As soon as Ythe vehicle wheel grips the shield I 6instead of the roll I the'shield shifts across and comes to rest uponthe roll. The vehicle immediately begins to move backward over the coverplate andoff the machine. The intereng'agement of theshield and therollis suflicient to act as a stop for the shield, but Yadditional stopmeansV may readily be provided,ifdesired. n Y

Normally it is vnot Vnecessary to test a `vehicle with its wheelsrotating in the reverse direction. but'when this is desirable suitablemeans may be provided to render the clutch 9 inoperative to rotate theshaft I8. Fingers 96, later described,

l furnish a means to this end. In this manner the, shields I6 will notbe moved into roll--cover-` ing position by the reverse rotation of thevehicle wheels. Y

, The preferred typer of overrunningclutch mechanism 9'is'shown inFigures 4 and 5. It consists of a casing 99 which houses gripping camsor eccentrics 9|, preferably in thev formV of i circular disks, whichare pivotcd to thc housing 9o at su.v

Such' pivots, as shown in Figure 4, are located near theV peripheries ofthe respective eccentric members 9|l andare secured inthe housing atpoints spaced from the solid shaft 20, which 1s in effect a continuationor extension of the hollow roll shaft I 4. The spacing of the pivots ofY to turn with the shaft.

I6, or, alternatively, such arml may be'anchored Y to hold the casingstationary or employed to actuate other mechanism.y 'When connected tothe cover plate operating mechanism itwill be evident that slightrotation of shaft 29 ina clockwise direction, as viewed in Figure 4,will result inA the plate being moved into operative roll-cov'- e eringposition in the manner illustrated in Figures 1 and 2. If, on the otherhand, it is'desired merely to hold the rolls from rotating with-Y outthe provision of cover plates, one of the other arrangements mentionedAmay be used. If the arm 93 is merely 'anchored to hold casing 90stationary, pressure of shaft'29, tending to rotate in a. clockwisedirection against the eccen- -trics 9|, will result in these membersgripping the shaft suiiciently tightly to hold it against furtherrotation in this direction. Y vSince the roll is secured to such shaftit, in turn, will be locked. As Y soon as the shaft ris rotated in theopposite or counterclockwise direction, however, the eccentrics 9I willimmediately bereleased to permit such rotation.

As another alternative, instead of arm 98 being locked, it may, as shownin Figure 6, bev connected to suitableoperating mechanism of an internalexpanding brake band 99, which may be located within the, end cfa rollI, to engage the inner-,side of its shell. Normal forward rotation tendsto drive'the roll I counterclockwise e as shown by the arrow'B. lWhenthe direction of rotation of the wheel is reversed, tending to rotatethe roll I in the direction shown by the arrow C, the tendency isimmediately to tighten Y the band 99 yinto engagement with the'roll. The

particular construction of the vinternal vbrake mechanismis not partofmy invention, and it Y `for driving thereover off the rolls.

l'7. In a vehicle testing machine, in combination with a pair of rollsspaced apart to vcradle a vehicle wheel therebetween, a roll shieldplate movable to cover the upper side of one of said K rolls, a support,a shaft journaled in said support, y A V means driving said shaft insynchronism with rotation of one roll of saidV pair, and apivoted armoperatively connected to said'shaft and Yto said shield plate, swingableby rotation of said shaft in a sense the reverse of the shaftssense `ofrotation `during a. testing operation, to move said plate from aretracted position wherein-it is out of contact with said rolls and thewheel, to an operative position wherein it overlies one roll of saidpair and is supportingly engaged beneath the wheel, fordriving thereoveroff the rolls,

8. In a vehicle testing machine, in combination with a pair of rotatablerolls spacedlapart to cradle a, driving wheel of an automotive vehicle,a wheel supporting plate member, and means guiding 'said wheelsupporting plate member for movement fromfan inoperative position,wherein it is out'of contact with the wheel so cradled, into anoperative position, wherein the member may constitute the entire supportfor the wheel,l andby such support affording traction for driving offthe rolls. Y f f 9. In a vehicle testing machine, in combination with apair of rolls spaced apart to cradle a vehicle wheel therebetween, and aroll shaft rotating with one of said rolls, a roll shield plate movableto cover the upper side of one of said rolls, a support, a rock shaftjournaledinfsaid support, a rockshaft rotating member operativelyconnected to turn said rock shaft, va plurality of disks disposed inspaced relationship circumferentially about said roll shaft-and pivotedeccentrically on said rock shaft rotating member lin position forengaging thev roll shaft simultaneously, said roll shaft, by rotation ina given direction, swinging said eccentric disks simultaneously awayfrom it, and by its initial rotation in the reverse direction slightlyswinging said eccentric disks in the opposite direction and pressingagainst the'disk's', Vand through them exerting force upon their pivotsto turn said rock shaft rotating member, and an arm pivoted to said rockshaft and to said shield plate, movable by rotation of -said shaft toshift said plate from a retracted position out of contact with saidrolls and the wheel cradled thereby into an operative position overlyingone roll of said pair and supportingly engaged beneath the wheel fordriving thereover on the rolls. g f

10. In a powertesting device or Ithe like, in-

cluding rolls spaced apart to cradle a driving wheel of an automobile, atraction member en- L guided for movement between an operative position,wherein it overlies-one o-f said rollsand tractively engages beneathVthe wheel, andaretracted position wherein it is out of contact with thewheel, and means guiding-said shield for movement into such operativeposition, for driving oi said rolls.- Y

12. In a vehicle testing machine, in combination with a pair of rollsspaced apart to cradle a vehicle drive wheel therebetween, a roll shieldguided for movementbetween an operative position, wherein it overliesone of said rollsand tractively engages beneath' the wheel, and aretracted position wherein it is out of contact'with the wheel, andmeans automatically operable upon reverse rotation of therolls tol movesaid shield into such-operative position, for driving off said rolls. fl

13. In avehicle testing machine, in combination with a pair of lrollsspaced apart to cradle a vehicle drive wheel therebetween, a roll shieldguided for movement between an operative position, wherein .it overliesone of said rolls and. tractively engages beneath the wheel, and aretracted position wherein it is out of contact with the wheel, and anoperative connection between said shield and one of said rolls,including an overrunning clutch associated with said roll, to

move said shield automatically into such opera-`

